NUMBER AND EVALUATION OF SOMATIC-CELLS IN THE MILK OF GOATS AND SHEEP

During a two years research program besides bacteriological and chemical residue parameters somatic cells in milk from goats and ewes were counted. Aim of these examinations was to answer the following questions: 1. Are the estabilished methods for cow's milk also applicable for milk from goats and ewes? 2. Are the claimed values for cow's milk also to be kept and suitable under hygienic aspects for the milk of these animals? Compared to the optical cell counting acc. to BREED it could be shown that the FOSSOMATIC-method without any restrictions may be used. Within a range from 10(4)-10(7) cells/ml correlation coefficients were found of r = 0,967 resp. r = 0,975. The physiological number of somatic cells was evaluated in uninfected glands and animal bulk samples in an analysis of time series up to 17 days in different herds. Hereby, a geometric mean value of 337 000 cells/ml for goat's milk and 111 000 cells/ml for ewes's milk could be determined. The median values of cumulative distributions and also the mode values of frequency distributions were found in the same range. The evaluation of threshold values in the sense of legislative prescriptions is based on 69 resp. 56 bulk milk samples from goat's and ewe's herds in 6 different countries ("Lander") of Germany. From the cumulative distribution it can be seen that regarding the present and further limits for cow's milk (500 000 resp. 400 000 cells/ml) only 30 % resp. 20 % of goat's milk and 50 % rsp. 45 % of ewe's milk remain under these values. These results at least partly may be explained by the higher physiological numbers of somatic cells in these animals. Under practical conditions and regarding the experience in cow's milk a limit value of 1 000 000 cells/ml for goat's milk and of 600 000 cells/ml for ewe's milk could be realistic.